When I was asked for some images I specifically asked what size, dpi, colour space and file type they wanted. I got back very specific details and was able to meet their requirements but this was from a photography magazine, so if you are dealing with a sports mag they may not know themselves?
If that's the case I would try to find out what size they will be printed at and then submit the shots at 300dpi in RGB and to those dimensions in .tiff format. Don't forget to include all your details in the tags and your name/contact on the cd/dvd as well if submitting in hard format
